The 29-year-old is a long-term favourite of Jose Mourinho's, having impressed upon being brought to Stamford Bridge by the Portuguese in 2013.

Mourinho is understood to have approached the Brazil international in the past, most recently making his interest known last summer, and the Manchester Evening News suggests that a move between the clubs could still be on.

Willian, who is a part of Brazil's 23-man squad for the World Cup, has two years left to run on his existing deal and may be offloaded if he indicates that he wants out.

However, United have not done any business with Willian's agent Kia Joorabchian since Carlos Tevez's controversial switch to Manchester City nearly a decade ago.